High speed printing with super-fast inks



ly 21, 6 D. J. BERNARD! ETAL 3,

HIGH SPEED PRINTING WITH SUPER-FAST INKS Filed Nov. 21, 1961 United States Patent 3,141,408 HIGH SPEED PRINTING WITH SUPER-FAST INKS Dominic J. Bernardi, Bolulan V. Burachinsky, and Robert S. Czeropski, Scarsdale, N.Y., assignors to Interchemical Corporatiom'New York, N.Y., a corporation of Ohio Filed Nov. 21, 1961, Ser. No. 153,801 2 Claims. .(Cl. 101-426) This invention relates to typographic and lithographic high speed printing with super-fast inks whose vehicles comprise resin solutions in organic solvents, preferably petroleum derived solvents having boiling ranges between 350 to 425 F. and alcohol and glycol solvents having similar boiling ranges.

In ink distribution equipment for high speed printing, including typographic and lithographic printing, the ink is picked up from a fountain by a roller and is transferred to other rollers, alternately metal and rubber, to produce eventually on the plate an even film a few ten-thousands of an inch in thickness. At least eight, and generally from ten to twenty, rollers are used in such equipment herein referred to as extended ink distribution systems, the expression commonly used for such equipment. In each transfer of ink, the thin ink film is literally torn in two, part remaining on the original roller, part transferring to the next roller. The work done in splitting the film produces heat: temperatures of 90 to 100 F. and higher can be observed on some presses even where the metal rollers are water cooled. During the splitting, the film is pulled into innumerable thin filaments of less than 1 mil diameter, and in this form is exposed ten to twenty times to the atmosphere around the distribution system, with a relative movement at press speeds equivalent to 15 to 20 miles per hour. This extreme exposure of the film has limited conventional typographic and lithographic ink vehicles to relatively slowly evaporating solvents.

Printing procedures employing super-fast inks having relatively low boiling solvent bases have been proposed involving the utilization of an enclosure for the distribution system, into which enclosure is introduced a gas containing a high concentration of ink solvent vapor to minimize volatilization of the solvent and maintain the ink comparatively stable in the distribution system (US. Patent 2,972,301). This expedient of utilizing an enclosed extended distribution system having therein a high concentration of ink solvent vapor has been suggested for extended ink distribution systems in which some of the metal rollers are water cooled. The circulation of cooling water through the metal rollers, usually the ink storage roller of the system, invariably is carried out to maintain the cooled roller near the normal press temperature which, unless the press room is air-conditioned to control the temperature to say about -70 F., is invariably several degrees above the prevailing room temperature of from 70 to about 90 F.

It has also been proposed to feed directly into the advancing nip between the rollers of the distribution system a gas, in whose atmosphere the ink will not dry in the time required for distribution, at such a rate that a film of the gas a few thousandths of an inch in thickness is maintained on the rollers (US. Patent 2,972,303).

Ink distribution systems involving enclosures with the maintenance therein of an atmosphere saturated with solvent vapors, while permitting the use of super-fast inks in printing and enabling printing at speeds of 1200 to 1500 feet per minute and faster, have been found objectionable, among other reasons, because of the added difficulties the enclosures interpose to the workmens inspection of the printing as its proceeds. Moreover,

critical.

3,141,408 Patented July 21, 1964 "ice such enclosures complicate the making of the necessary adjustments to the printing to obtain best results. Workmen find the solvent vapor saturated atmosphere objec tionable, chiefly because of its odor. The suggested procedure of introducing a current of gas into the nip between the rollers has also been found objectionable by workmen because of the odor of the gas.

It is among the objects of the present invention to provide a process for high speed printing employing a press having an extended distribution system in which the objections of heretofore known procedures, such as the necessity of having the distribution system enclosed or the provision of a saturated atmosphere containing solvent vapors in the vicinity of the distribution system are eliminated.

It is another object to provide such process employing super-fast inks with consequent quick drying of the printed paper by passage thereof through a heater or oven maintained at a temperature adequate to dry the ink and below the temperature at which the paper would be deleteriously affected.

Other objects and advantages of the present invention will be apparent from the following detailed description thereof.

In accordance with this invention, all or substantially all of the rollers of the extended distribution system using super-fast inks are cooled by passage therethrough of an adequate amount of a suitable cooling medium, preferably cold water, having an inlet temperature not exceeding about 40 F., thus effecting the removal of the heat generated in splitting the film and, equally important, maintaining substantially all of the rollers of the distribution system, including the rubber rollers, at temperatures such that at no point in the distribution system is. the ink hardened or rendered unduly viscous so that it will interfere with the working up of the ink into the thin, uniform films on the rollers which effiect transfer of the film of ink to the printing plate. The rollers are thus cooled to maintain the temperature of the ink films thereon within the range of from about 40 to about 65 F., i.e., below about 65 F. and above the temperature where the film becomes excessively viscous on the rollers under the conditions of operation, which increase in viscosity would cause picking of the paper surface, i.e., removal of fibers or coating material from the surface of the paper by excessively viscous ink. By cooling all or substantially all of the rollers of the extended distribution system as herein described, surprisingly, the ink remains stable and free-flowing, and this without the utilization of enclosures or special atmospheres saturated with solvent vapor, and the ink in a thin, even film is supplied to the plate, with excellent printing results at high speeds, over 1,000 feet per minute and within the range of from 1,000 to 2,500 feet per minute. Thus the present invention permits printing at speeds above 1,000 feet per minute with the drying of the printed paper at relatively low paper temperatures of the order of 200 F., hence utilizing less heat and producing printed paper which contains substantially all of its original moisture content so that the paper is not weakened by the printing operation.

The upper and lower limits of the temperature range of from about 40 to 65 F. for the temperature of the ink films on the rollers, including the rubber rollers, are If the ink films on the rollers are not cooled to a temperature of about 65 F. or lower, excessive volatilization of the solvent of the super-fast ink takes place with consequent loss of stability of the ink, formation of uneven films and ghosts in the printing. Cooling to below 40 F. on the other hand may result in undesirable hardening of the ink films with consequent formation of uneven films and ghosts. It is important to note that the temperature range of from about 40 F.

2) to about 65 F. refers to the temperature of the ink films on the distributor rollers.

To explain the invention more fully, reference is had to the accompanying drawing which discloses schematically the distribution system of one unit of a press, which distribution system can be used to practice this invention. It will be appreciated that any desired number of units, each equipped with such distribution system, can be used, and in multi-color printing one such unit is used for each color.

A web of paper is fed through the press by appropriate feed rollers 11. The plate 12 is inked by the distribution system which comprises a series of rollers operating betwen the fountain 14 and the plate 12. The metal fountain roller 15 takes ink from the fountain 14 and transfers it to a rubber ductor roller 16, from which it is transferred to a metal roller 17, thence to a rubber roller 18, and thence to a metal ink storage roller 10. A rubber idler roller 21 transfers the ink to a metal roller 22 which in turn transfers the ink to the rubber form rollers 23, 24 which are in frictional contact with the rotating plate 12.

Rubber smoothing roller 25 is in frictional contact with plate 12 to effect smoothing of the ink thereon. Roller 25 is in frictional engagement with the metal smoothing roller 26 rotating in peripheral contact with the rubber distributing roller 27 and the rubber distributing roller 28. Lower steel distributing roller 29 rotates with its periphery in contact with the periphery of the rubber distributing roller 27. These rollers are driven by a conventional gear drive on the gear side of the press.

In accordance with this invention, all of the rollers 17 to 29, inclusive, the rubber as well as the metal rollers, are cooled to dissipate the heat generated during operation and to maintain the ink films on the rollers at a temperature within the range of from 40 to 65 F. This is accomplished by circulating cold water, say, at a temperature of about 40 F. or less, or other cooling medium, through the interior of each roller. The cold water, for example, may be supplied to the interior of each roller from a common header having a line, one for each roller, leading into one end of the roller. The water is pumped through each roller, and discharged from the opposite end into a common main from which the heated water is passed through a suitable refrigeration system which cools the water to its original inlet temperature of 40 F. or less for return to the respective rollers. Preferably, but not necessarily, the fountain roller 15 and the ductor roller 16, as well as the rubber rollers 18, 21, 23, 24, 25, 27 and 28 and the metal rollers 17, U, 22, 26 and 29 are cooled by flowing therethrough in heat exchange relation with the periphery thereof a suitable cooling medium such as cold water at a temperature not exceeding about 40 F. Good results are obtained by so cooling substantially all of the rollers 17 to 29, inclusive, without cooling the fountain roller 15 and the ductor roller 16, although for best results all of the rollers of the distribution system are cooled.

It will be appreciated the ink film on the rollers can be maintained within the range of from 40 to 65 F. by cooling substantially all of the rollers 17 to 29, inclusive (say, neglecting to cool one or two of the rollers 17 to 29), and this invention includes such operations and is not limited to the preferred processes in which all of the rollers 17 to 29 are cooled as herein described.

The super-fast inks used in the operation of the process of this invention contained to 50% by volume of an organic solvent, preferably an aliphatic hydrocarbon solvent having a boiling range of from 300 to 425 F., preferably 365 to 400 F., polyglycols (e.g., propylene glycol), glycol others or aliphatic alcohols, having boiling points within the range of from 300 to 425 F., or mixtures of such solvents, e.g., mixtures of alcohols, or of glycols or glycol ethers, alcohols and glycols, alcohols and glycol ethers, etc., which mixtures boil within the range of from 300 to 425 F. By boiling range is meant that approximately 5% of the solvent goes off at the minimum temperature and 9 5% or more goes off at the maximum temperature. Thus with an organic solvent having a boiling range of from 365 to 400 F., approximately 5% of the solvent will go off overhead when heated to 365 F. and at least of the solvent will go off overhead at 400 F.

The particular amount of solvent used in any ink depends on the other constituents, chiefly the dye or pigment employed to form the color. In the case of light colored inks such as chrome yellow, approximately 37% solvent is used; for dark inks, particularly the blacks, about 30% to 35% solvent is used; for inks in which the color is supplied by organic dyes 30% to 35% solvent is used. All percentages herein are on a weight basis.

The resinous constituent of the ink can be any of the known resins used in compounding super-fast inks. Exemplary resins are limed rosin; pentaerythritol ester of rosin; pentaerythritol maleated or fumarated rosin; dimerized rosin, limed or unlimed; pentaerythritol ester of dimerized rosin; Utah coal resin; (a resin consisting essentially of carbon and hydrogen, having an average molecular weight of 1,000 and a refractive index of 1.544 and occurring in Utah resin-bearing coals); hydrocarbon resins; rosin-modifying phenolic resins; Gilsonite, etc. The amount of resin in the ink generally is from 20% to 50% by weight of the ink.

Examples of super-fast inks suitable for printing in accordance with this invention are as follows:

ABlack Ink Percent Pentaerythritol Ester of Rosin 24.6 Limed Rosin 5.4

Gilsonite 9.7

Talc 2.0 Carbon Black 21.0 Methyl Violet Toner .5 Octyl Alcohol 2.0 Hydrocarbon SolventBoiling Range 365400 Total A-1 Black Ink Percent Pentaerythritol Ester of Rosin 34.4 Rosin 2.1 Gilsonite 3.9 Carbon Black 21.0 Talc 2.0 Methyl Violet Toner 2.0 Hexyl Alcohol 2.0 Hydrocarbon SolventBoiling Range 365-400 Total 100 A-2 Black Ink Percent Carbon Black 17.0 Alkali Blue Toner 8.0 Talc 2.0 Gel Compound 5.0 Bodied Linseed Oil 5.0 Pentaerythritol Ester of Fumarated Rosin 32.2 Hydrocarbon SolventBoiling Range 365400 5, BYellw Ink Percent Medium Chrome Yellow 15.8 Benzidine Yellow 5.5 Pentaerythritol Ester of Fumarated Rosin 38.2

Calcium Carbonate 3.1 Hydrocarbon SolventBoiling Range 365-400 Total 100 CRed Ink Percent Red Lake B 15.6 Barium Lithol Red 4.1 Calcium Carbonate 2.5 Pentaerythritol Ester of Fumarated Rosin 36.5 Hydrocarbon SolventBoiling Range 365400 Total 100 DBlue Ink Percent Peacock Blue Lake 21.1 Alkali Blue 1.6 Pentaerythritol Ester of Fumarated Rosin 33.2 Clay 13.6 Hydrocarbon SolventBoiling Range 365400 Total 100 While a limited number of inks have been disclosed, all made with hydrocarbon solvents having boiling ranges of from 365 to 400 F., it will be appreciated that a wide variety of inks containing hydrocarbon as well as polyglycol, glycol ethers and mixtures of glycol and glycol ether solvents can be used in this process. The binders incorporated in the ink may be any film-former which is compatible with the particular solvent employed and which gives a dry film when the solvent evaporates. The inks should not swell the rubber rollers; hence aliphatic hydrocarbon solvents are preferred as the solvent constituent of the ink, with or without small percentages of higher boiling alcohols.

The following example is given for illustrative purposes. It will be appreciated that this invention is not limited to this example.

In this example the ink used was the first black ink, the composition of which is given above.

The press used was a standard commercial printing press, the extended distribution system of which was modified to provide for flow of cooling water through all of the rollers. This distribution system was substantially the same as that shown in the drawing. The distri bution system was not enclosed.

Water at a temperature of 35.75 F. was supplied to each roller at a rate of '30 gallons per minute. The exit temperature of the water was 37.5 F.

The average temperature of the metal rollers was about F. The average tempera-ture of the rubber rollers was appreciably higher, about 70 F. The average temperature of the films of ink on the rollers was about F.

It will be appreciated that there is an appreciable difference in the temperature of the metal and rubber rollers. This is due to the difference in heat conductivity of these materials. The ink films on the metal rollers are cooled to a sufiiciently low temperature that when transferred to the rubber rollers under the temperature conditions noted, the films on the rubber rollers are not heated to an average temperature above about F. before being transferred to the next metal roller. The net efiect is that the average temperature of the films is maintained within the range of from about 40 F. to about 65 F.

Since certain changes in carrying out the above high speed printing process can be made without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawing shall be interpreted as illustrative and not in a limited sense.

What is claimed is:

1. In the method of printing on a moving web of paper moving at a speed through the press in excess of 1,000 feet per minute using a non-enclosed extended distribution system comprising alternate metal and rubber rollers with a super-fast ink constituted of a resin solution in an organic solvent having a boiling range of from 350 to 425 F., the improvement which comprises passing cooling water at a temperature not exceeding about 40 F. through substantially all of the rollers, including the rubber rollers, to cool the ink films thereon to a tempera ture below about 65 F. and above the temperature at which substantial hardening of the ink films on the rollers takes place, while maintaining the ink films on the rollers of the distribution system under atmospheric conditions.

2. In the method of printing on a moving web of paper moving at a speed through the press in excess of 1,000 feet per minute, using a non-enclosed extended distribution system of at least eight rollers, constituted of alternate metal and rubber rollers, with a super-fast ink comprising a resin solution in an aliphatic hydrocarbon solvent having a boiling range of from 365 to .400 F., the improvement which comprises passing cooling water through all of said rollers of the distribution system at an inlet temperature not exceeding about 40 F. to cool the ink films on said rollers and maintain said films at a temperature Within the range of from about 40 to 65 F., while maintaining the ink films on the rollers of the distribution system under atmospheric conditions.

References Cited in the file of this patent UNITED STATES PATENTS 2,268,594 Huber Jan. 6, 1942 2,866,410 Harless Dec. 30, 1958 2,972,298 De Marchi et al Feb. 21, 1961 2,972,303 De Marchi et a1 Feb. 21, 1961 

1. IN THE METHOD OF PRINTING ON A MOVING WEB OF PAPER MOVING AT A SPEED THROUGH THE PRESS IN EXCESS OF 1,000 FEET PER MINUTE USING A NON-ENCLOSED EXTENDED DISTRIBUTION SYSTEM COMPRISING ALTERNATE METAL AND RUBBER ROLLERS WITH A SUPER-FAST INK CONSTITUTED OF A RESIN SOLUTION IN AN ORGANIC SOLVENT HAVING A BOILING RANGE OF FROM 350* TO 425*F., THE IMPROVEMENT WHICH COMPRISES PASSING COOLING WATER AT A TEMPERATURE NOT EXCEEDING ABOUT 40*F. THROUGH SUBSTANTIALLY ALL OF THE ROLLERS, INCLUDING THE RUBBER ROLLERS, TO COOL THE INK FILMS THEREON TO A TEMPERATURE BELOW ABOUT 65*F. AND ABOVE THE TEMPERATURE AT WHICH SUBSTANTIAL HARDENING OF THE INK FILMS ON THE ROLLERS TAKES PLACE, WHILE MAINTAINING THE INK FILMS ON THE ROLLERS OF THE DISTRIBUTION SYSTEM UNDER ATMOSPHERIC CONDITIONS. 